In view of an increasing number of communication technologies and technological concepts in use, there is a trend of convergence of networks and systems based on such different technologies and concepts into overall network systems. Examples for such different technologies may include GPRS (General Packet Radio Service) or CDMA (Code Divisional Multiple Access) or, in general, IP-based (IP: Internet Protocol) mobile or fixed networks. Further, there is a trend of convergence of different services, functions and applications into overall network systems. Such converged network systems are often referred to as next generation networks. Examples for such next generation networks include networks specified by 3GPP (Third Generation Partnership Project) or IETF (Internet Engineering Task Force) or TISPAN (Telecom and Internet Converged Services and Protocols for Advanced Networks).
An example of standardization efforts in this field includes the 3GPP work on system architecture evolution (SAE) and/or long-term evolution (LTE). This work includes among others GPRS enhancements for E-UTRAN (Evolved Universal Terrestrial Radio Access Network) access, as for example specified in 3GPP TS 23.401 V8.7.0, and architecture enhancements for non-3GPP access, as for example specified in 3GPP TS 23.402 V8.7.0.
The specification 3GPP TS 23.401, covers both roaming and non-roaming scenarios and related aspects, including mobility between E-UTRAN and pre-E-UTRAN 3GPP radio access technologies, policy control and charging, and authentication. The specification 3GPP TS 23.402 specifies a provision of IP connectivity using non-3GPP accesses to the evolved 3GPP packet-switched domain.
In a network a plurality of sessions may be provided for a single network device or user.